The invention concerns a machine for mowing stalk-like crop having several intake and mowing arrangements arranged in side-to-side spaced relationship to each other for the cutting and conveying of the crop and at a rear side of which a conveying channel is provided through which the cut crop can be conveyed to a forage harvester.
A mowing arrangement for stalk-like cereal crop is described in DE 195 27 607 A which is equipped with four conveying and mowing disks distributed over the operating width. The crop is mowed by the conveying and mowing disks, transported in pocket-shaped recesses at their rear sides and cleaned out of the pocket-shaped recesses by clean-out disks rotating in the same direction. The crop is then transported by the clean-out disks along the rear wall of the mowing arrangement until it is taken over by the rear side of a conveying and mowing disk arranged further inward. Thereby the crop is transported along the rear wall in alternating turns by the conveying and mowing disks and by the clean-out disks.
EP 0 760 200 A discloses another machine for the mowing of stalk-like crop in which several intake and mowing drums are distributed over the operating width. The crop is transported at the rear side of the intake and mowing drums inward along the rear all while it is conveyed in the gore region between adjoining intake and mowing drums by transverse conveying drums, that extend through slots in the rear wall.
EP 1 008 291 A proposes a further machine for the harvesting of stalk-like crop that is equipped with several drum-shaped intake elements distributed over the operating width for taking up and conveying of the crop. The crop is conducted by the take-up to an independent transverse conveyor that is arranged behind the take-up elements in the forward direction of operation. The transverse conveyor conveys the crop along a guide wall that is arranged immediately behind the take-up elements. The transverse conveyors are conveyor drums or conveyor belts.
Regardless of the question whether the crop is conveyed in the conveying channel to the center of the machine by means of the intake and mowing drums (DE 195 27 607 A, EP 0 760 200 A) or a transverse conveyor independent of these (EP 1 008 291 A), it has been shown that the dimensioning of the conveying channel is problematic. If its width is selected so large that it can accept even the largest conceivable amounts, then with small amounts of throughput, the crop is poorly retained and conveyed, since it does not fill the conveying channel and does not interact in a satisfactory way with the conveying elements. If the width of the conveying channel is reduced, it cannot accept larger amounts of conveyed crop which can result in jams.
The problem underlying the invention is seen in the need to define a machine for the mowing of stalk-like crop that can satisfactorily process smaller as well as larger amounts of conveyed crop.
This problem is solved according to the invention by providing the machine for mowing of stalk-like crop with a conveying channel having a width which is adjustable as a function of the amount of harvested crop present. In this way, an automatic conforming of the width of the conveying channel to the amount of crop conveyed is attained. With small amounts of crop, the conveying channel is restricted by the width defining element, so that the crop is retained and transported securely even with a small throughput. On the other hand, with larger amounts of throughput, the width definition element opens the entire width of the conveying channel so that no jams develop.
In order to control the movement of the width definition element, the use of an electronic control would fundamentally be conceivable which detects the immediate flow of the crop by optical, capacitive or other sensors and moves the width definition element by means of actuators, for example, electric motors, electromagnets or hydraulic cylinders. However, for reasons of cost, a practical solution is to have the width definition element be repositioned by the crop itself. In this embodiment, the width definition element is loaded by a force. The crop moves the width definition element against this force into a position in which the conveying channel is widened. If the intensity of the flow of the crop is later reduced, the width definition element is again brought into that position in which the conveying channel is narrowed by means of the force.
The force against which the crop moves the width definition element, is preferably generated by a spring of any desired type. The spring may have a range of motion that is limited by stops. It can also be provided with a pre-load when the width definition element is in a rest position, that is, when there is no flow of crop, so that a force differing from zero must be applied in order to move the width definition element out of the rest position. The use of a weight would also be conceivable that is connected over rope pulls and/or deflecting levers to the width definition element and generates the force needed to be applied to the width definition element by the force of gravity.
In principle, it would be possible to configure the width definition element as a driven conveying element. In that way, intake and mowing arrangements, which transport the harvested crop along their rear sides, could be used as a width definition element and supported in bearings, free to move. Transverse conveying drums and/or clean-out discs used for conveying the crop may also be provided as movable width definition elements. Alternatively, separate conveying elements that convey the crop to the center of the machine independently of the intake and mowing arrangements, could be used as width definition elements. However, since it is technically costly to drive movable elements, a practical solution is to configure the width definition element as a guide element that is not driven.
In many cases, the amount of crop conveyed changes over the length of the conveying channel, since harvested crop from the outer intake and mowing arrangements is added to the harvested crop from the inner intake and mowing arrangements. It must therefore be preferred that the width definition element be arranged to define a width of the conveying channel that varies over the length of the conveying channel.
This varying width can be attained fundamentally in two ways. On one hand, a width definition element is conceivable that is formed and attached in the conveying channel in such a way that the width of the conveying channel depends in the desired way on the immediate position. As a rule, it will be smaller in the outer region than further inward. In case a greater flow of crop occurs, the width definition element is moved as a whole, so that a widening of the conveying channel occurs. Thereby, a predetermined change in the width of the width definition element occurs over its entire length. It can be selected so as to be constant over the entire length of the width definition element or in such a way that the conveying channel is wider at the inner end by a fixed percentage more that the width of the outer end. Such a change in width can be attained by a width definition element that is rigid in itself and can be moved and guided in the transverse direction or at an angle to the conveying channel.
Indeed, the flow of the crop supplied by the individual intake and mowing arrangements, which is successively conducted to the flow of the crop in the conveying channel, is not always homogeneous. There may, for example, be irregularities in the stand of the crop, that lead to the fact that the flow of the crop does not increase in the inward direction as would be expected from a homogeneous stand of the crop. In a change of the width predetermined over the length of the width definition element, this would result in a less than optimal conveying of the crop in one of the regions. Therefore, on the other hand, a practical solution is that the width definition element can be varied over its length corresponding to the local quantities to be conveyed. For this purpose, the width definition element can be composed of individual independent elements that follow each other in the longitudinal direction of the conveying channel and/or elements flexible in themselves and/or be supported in bearings, free to pivot, about an at least approximately vertical axis.
In order to keep the number of parts small, a practical solution is to use only a single width definition element, that essentially extends over the length of the conveying channel. It would also be possible to use single, individual width definition elements, arranged in the longitudinal direction of the conveying channel, behind each other, that are configured as rigid elements, or in order to reduce the friction, as rolls or pulleys, free to rotate. The latter may be suspended separately, free to move against a force.
The width definition element is preferably configured in the form of a skid. Its surface is relatively small, so that only a small amount of friction occurs in the contact with the conveyed crop. Furthermore, in case of wear, only a small and low cost single element need be exchanged. It would also be conceivable to use a wall bordering the conveying channel as a movable width definition element.
The invention is preferably applied to a machine in which the harvested crop is conducted in a conveying channel oriented transverse to the forward operating direction, that is located on the rear side of the intake and mowing arrangements and is defined on its rear side by a rear wall. Here the transverse transport can be performed through the rear sides of the intake and mowing arrangements interacting with transverse conveyor drums and/or clean-out disks along the rear wall. In such a machine, the width definition element is arranged between the intake and mowing arrangements and the rear wall, so that the conveying channel is defined between the intake and mowing arrangements and the width definition element moves in the direction towards the rear wall when the flow of the crop increases. In this embodiment, the shape of the width definition element conforms to the wave form of the rear wall.